[Velchronus]

The first source has a history section that details the Senate and House votes. There is no record of the votes because it was passed by unanimous consent in the Senate and without challenge in the House.

The NALC actually deleted their page in support of the legislation but luckily it's archived: https://web.archive.org/web/20130805121847/https://www.nalc....

> Thanks to NALC and a coalition of other unions (the Rural Letter Carriers and the Mail Handlers), management associations, vendors and mailers, Congress rejected almost all the negative recommendations of President Bush’s blue-ribbon Commission on the Postal Service. Instead it crafted a balanced compromise that emphasized pragmatism over ideology.

> Rep. Henry Waxman (D-CA) and Sen. Tom Carper (D-DE) were instrumental in negotiating the final details with Sen. Susan Collins (R-ME), the bill’s chief sponsor in the Senate. In an e-Activist message sent on December 9, NALC President Bill Young thanked Waxman and Carper for advocating NALC’s interests in the legislation. He also thanked Sens. Joe Lieberman (D-CT) and Daniel Akaka (D-HI), and Reps. Tom Davis (R-VA), Danny Davis (D-IL) and John McHugh (R-NY) for their roles over the years.